Hexen II: Hammer of Thyrion

TODO:
---------------------------

- Add a pak-patch application for Mac OS X.
- Revise the launcher GUI.
- Add joystick support through sdl
- Re-visit the mouse grab code and clean it up.
- Do a clean-up of the opengl system
- Add multisampling support to win32
- Maybe add support for several image formats (jpeg, png, etc)
- Software renderer: revisit the FoundTrans / TransCount usage
  in non-intel code (d_edge.c, r_edge.c).
- Software renderer: maybe add 16 bit support (r_pixbytes = 2,
  and even 4 for 32 bit)? The current code is largely missing
  translucency pieces and the d_8to16 and d_8to24 translation
  tables.
- Add a direct draw video driver, like the one in quake2, for
  mgl-free win64 software renderer support
- Add sequencer (mpu-401) support for midi (alsa / oss)
- MIDI-background music: re-write with proper decoder library
  usage (eg. wildmidi/timidity for software-midi, ogg-vorbis
  for ogg, etc., like in quake3); reserve one of the available
  channels for this purpose. a lot of work, but that will free
  us from the SDL_mixer dependancy on linux/unix (and from the
  quicktime dependancy on OSX): opening the sound device twice
  is not a good thing. and we won't be needing any crap such as
  fmod or other habaloo for windows external music.
- Add pthread support to the utilities and revise the current
  windows threads mess there. the alpha ifdefs need cleaning.
- utils/jsh2colour: clean-up the huge mess and improve a bit.
- utils/maputils: improvements on the light tool?
- utils/texutils: add some more texture tools (pcx2wal, etc.)
- More unification of hexen2 and hexenworld trees
- Reduce the number of lines in BUGS ;)
- Re-visit the extra patches, fix and merge (e.g.: fog, etc.)